In a previous study, we determined that in individuals with abnormally low active α1PI levels, CD4 counts exhibit sinusoidal cycling with 23 day periodicity. Wave form appearance of CD4 cells with a peak every 23 days is a pattern that is indicative of adult thymopoiesis. We showed that in response to α1PI therapy, HIV infected and uninfected individuals exhibited an increased CD4 counts axis of oscillation, but no change in periodicity. In contrast, one uninfected individual who was not receiving therapy, exhibited no change in the axis of oscillation, but periodicity was 27 days. Human adult thymopoiesis is not well characterized, and based on these results, we have two hypotheses.